st account of them in the Transactions of the Royal Society was
presented in the year 1667. A description of early gas-lighting has been
reserved for a later chapter, but the foregoing is noted at this point
to introduce a novel early method of lighting in coal-mines where
inflammable gases were encountered. In discussing this coal-gas another
early writer stated that "it will not take fire except by flame" and
that "sparks do not affect it." One of the early solutions of the
problem of artificial lighting under such conditions is summarized as
follows:

Before the invention of Sir Humphrey Davy's Safety Lamp, this
property of the gas gave rise to a variety of contrivances for
affording the miners sufficient light to pursue their
operations; and one of the most useful of these inventions was
a mill for producing light by sparks elicited by the collision
of flint and steel.

Such a stream of sparks may appear a very crude and unsatisfactory
solution as judged by present standards, but it was at least an
ingenious application of the facilities available at that time. Various
other devices were resorted to in the coal-mines before the introduction
of a safety lamp.

In discussing the candle it is necessary again to go back to an early
period, for it slowly evolved in the course of many centuries. It is the
natural descendant of the rushlight, the grease-lamp, and various
primitive devices. Until the advent of the more scientific age of
artificial lighting, the candle stood preeminent among early
light-sources. It did not emit appreciable smoke or odor and it was
conveniently portable and less fragile than the oil-lamp. Candles have
been used throughout the Christian era and some authorities are inclined
to attribute their origin to the Phoenicians. It is known that the
Romans used them, especially the wax-candles, in religious ceremonies.
The Phoenicians introduced them into Byzantium, but they disappeared
under the Turkish rule and did not come into use again until the twelfth
century.

The wax-candle was very much more expensive than the tallow-candle until
the fifteenth century, when its relative cost was somewhat reduced,
bringing it within the means of a greater proportion of the people.
Nevertheless it has long been used, chiefly by the wealthy; the
departing guest of the early Victorian inn would be likely to find an
item on his bill such as this: "For a gentleman who called himsel